Something's amiss. I have 4 fruit trees in a row approximately 60' long. The Clementine is in the middle. Last year it gave 1 fruit. This year I added compost and mulch in November and January. Had flowers and lots of fruit which is now turning yellow or brown and falling off. The leaves are a bit leathery, yellowing and not looking good. I added Bandini 15-15-15 fertilizer in March which helped some.
The other Valencia Orange, Lemon and Lime are doing fine.